There’s a lot of buzz around intermittent fasting – and for good reason. Intermittent fasting is an amazing longevity hack! So, is there ever a time or situation where intermittent fasting may do more harm than good for the body?

First, let’s look at what intermittent fasting is, its benefits and some common ways of doing it.

What is Intermittent Fasting?

Intermittent fasting is a way of eating that alternates between fasting and eating on a regular schedule. There are different schedules or ways to intermittent fast. A few of the most popular ways to interment fast are:

• Daily Time Restricted Eating: A 16/8 fast is a common example of this schedule where you’d eat in an 8-hour window and fast for 16 hours.
• 5:2 Approach: You eat regularly five days a week. For the other two days, you limit yourself to one 500–600 calorie meal or just water for those two days.  
• Alternate Day Fasting. You eat a normal diet one day and either completely fast or have one small meal (less than 500 calories) the next day.

It can take the body 2-4 weeks to adjust to intermittent fasting. You may feel tired and cranky as your body adjusts. However, many people feel better and enjoy the benefits of intermittent fasting and stick with it once they’re bodies have adjusted to it.

What are the Benefits of Intermittent Fasting?

Research shows numerous benefits of intermittent fasting, including:

• Weight loss: This happens when after hours without food, the body exhausts its sugar stores. The body then starts burning fat, something called metabolic switching.
• Sharper mind: Studies show intermittent fasting boosts working memory in animals and verbal memory in adult humans.
• Protection from chronic disease: In part, intermittent fasting can stave off chronic disease due to its ability to lower inflammation, a contributor to every age-related chronic disease.
• Heart health: Research shows intermittent fasting improved blood pressure and resting heart rates.
• Longer life: The overall health benefits of intermittent fasting may increase both your health span (how long you live well) and lifespan (how many years you live).

Is Intermittent Fasting Always Good for You?

With all these good reasons to intermittent fast, is there ever a time when intermittent fasting may do more harm than good? Here are some situations where it may be best to build up your health before testing the waters with intermittent fasting.

Metabolic Health and Intermittent Fasting

If your body is not metabolically healthy, intermittent fasting can backfire and be too taxing to the body. It may be better to take some time to build a stronger foundation of good health and get your metabolic health more stable.

The truth is that only 12% of Americans are metabolically healthy. Being at a healthy weight is a marker for metabolic health, but a person can be at a healthy weight and still be metabolically unhealthy. Poor metabolic health puts you at higher risk for Type II Diabetes, cardiovascular disease, and other diseases. 

Metabolic health is defined as having the following health markers in the normal range without medication for managing any of them:

• Blood glucose
• Triglycerides
• HDL cholesterol
• Blood pressure
• Waist circumference

When Can Intermittent Fasting Backfire?

While you don’t have to have every single one of the health markers noted above in perfect order, it’s a good idea to take some time to focus on getting these markers closer to or within the normal ranges before trying intermittent fasting. That said, it’s a bit of a catch 22 as intermittent fasting can have a positive impact on these health markers as well.

Here’s an example of how it can both help and hurt when it comes to blood sugar. If your blood glucose labs are significantly out of the normal range, intermittent fasting can backfire and cause further imbalance to your blood sugar. A better strategy to balance blood sugar would be to eat 3 balanced meals/day (balance of healthy carbs, fats and proteins) as this will help to balance and stabalize blood sugar.

On the other hand, if you work to get your blood sugar in better balance by eating 3 meals per day specifically designed to balance blood sugar, after a few weeks or months, you may see that your blood glucose labs have improved.

Now, with the body moving toward better metabolic health, intermittent fasting my benefit you. Wearing a continuous blood glucose monitor would be a good way to tell if intermittent fasting is harming or benefitting your blood sugar balance.

Here's another example to consider. If all of your metabolic markers are in the normal ranges with the exception of your waist circumference, intermittent fasting may be a good choice to help lose abdominal fat.

It really depends on how many markers for metabolic health are out of the normal range (and how far out of range) as well as other health conditions you may be dealing with as to whether intermittent fasting is a good choice for you or not.

In addition to metabolic health being a factor in how intermittent fasting will impact one’s health, here are some other considerations for when intermittent fasting may not be the best choice.

Differences Between Men and Women and Intermittent Fasting

Another consideration around intermittent fasting is that many of the studies on intermittent fasting were conducted with men. Women’s bodies are different. Women’s hormones and cycles (particularly if you are still menstruating) are different than men’s and more variable. If you are a woman and still having a period, it’s a good idea not to fast those few days before, during and after your period. Your body often needs more nourishment and rest. While intermittent fasting is full of benefits, it is a form of hormesis (good stress that makes the body more resilient), and around your cycle may not be the best time to stress the body in any way.

Endocrine Health: Adrenals and Thyroid

If you struggle with adrenal burnout or thyroid issues, notably any autoimmune diseases, be cautious with intermittent fasting. Again, what may be more nourishing to the body is to eat 3 meals designed to balance blood sugar and nourish your endocrine system. This way of eating is deeply nourishing to the adrenal glands, and what affects the adrenals affects the thyroid and vice versa. Adding further stress to the body with intermittent fasting may be too much strain on the delicate adrenal and thyroid glands.

Intermittent Fasting and Trauma or a Stressful Life Event

Trauma and stress tax our endocrine system, notably our adrenal glands, causing them to pump out excess cortisol (the stress hormone). If you are recovering from a traumatic or stressful life event, intermittent fasting may not be the best choice. Focusing on getting good sleep, eating balancing nourishing meals, and spending time doing things you enjoy with people who are uplifting will help you recover more quickly. Intermittent fasting will be waiting for you to try when you’re feeling more restored.

What to Do in Place of Intermittent Fasting to Benefit Your Health

At The Longevity School, we don’t adhere to rigid standards around wellness. While there are foundational elements to good health, some things that work well for one person may not for another. Each of us is unique and we need to honor those differences in our bodies. Learning to listen to your body and honor it is an important part of living the longevity lifestyle.

If you’re interested in getting healthier before jumping into intermittent fasting, our 4-week Longevity Jumpstart course will give you the tools to do just that.

Sources:

Prevalence of Optimal Metabolic Health and Nutrition Examination Survey 2009-2016, Journal Metabolic Syndrome and Related Disorders 

https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work